Microscope adjustment apparatus

ABSTRACT

In a microscope, a nosepiece support assembly and a coarse and fine adjustment mechanism in direct operative control of the support assembly, the support assembly including a nosepiece mounting carriage with a depending rod rigid therewith and mounting a cam follower which rides on the edge of a cam, rotation of which is controlled by the adjustment mechanism. The adjustment mechanism in turn includes a reduction gear assembly utilizing dual gear trains and mounted to a cam-mounting shaft externally of the frame of the microscope and housed within a coarse adjustment handwheel for immediate access thereto. One of the gear trains incorporates a compound gear having a torsion spring between the individual gears to enhance gear train interengagement throughout the gear assembly.

This is a divisional of co-pending application Ser. No. 627,318 filed onJuly 2, 1984 now U.S. Pat. No 4,573,771.

BACKGROUND OF THE INVENTION

The invention relates to microscopes, and is more particularly concernedwith the apparatus involved in the focusing of microscopes, includingnosepiece support assemblies, adjustment mechanisms, combining coarseand fine adjustment means for manipulation of a nosepiece supportassembly, and gear train systems as a component of the adjustmentmechanisms.

Microscope adjustment systems commonly provide mechanisms for adjustmentof the nosepiece relative to the stage which mechanisms incorporate bothcoarse and fine adjustment means, in many instances, controlling ashaft-mounted cam associated with linkage components which translaterotational movement of the cam into vertical adjustment of thenosepiece. Examples of such systems will be noted in the followingpatents:

U.S. Pat. No. 3,135,817; Wrigglesworth et al

U.S. Pat. No. 3,260,157; Boughton

U.S. Pat. No. 3,768.885; Boughton et al

SUMMARY OF THE INVENTION

The present invention is concerned with an adjustment system formicroscopes which constitutes a significant advance over prior artsystems in simplicity of construction, manner of operation and nosepieceadjustment, and most particularly in the ease of access to the operatingcomponents for purposes of servicing, repair or replacement.

Briefly, the vernier or fine adjustment utilizes a reduction gear trainsystem including dual parallel gear trains mounted as a unit within agear box. The gear box, as opposed to conventional microscopeconstruction, mounts externally of the arm assembly on an arm-traversingcam mounting shaft. The cam will be mounted, as is usual, internallywithin the arm assembly for engagement with the internally positionednosepiece support assembly.

It is significant that one of the dual gear trains incorporates acompound gear formed of independent reduction and pinion gears with aninterposed coiled torsion spring acting to rotationally bias the twogears in opposite directions as a means for preventing backlash withinthe gear trains and reducing lost motion, thus avoiding the necessity ofhighly precisioned formed gears. Similarly, the use of a spring loadedcompound gear allows for an automatic accommodation of the entire geartrain system to a degree of normal wear

The externally mounted gear box will itself be directly received withinthe coarse adjustment handwheel which will in effect provide a readilyremovable housing therefor. The assembly will be completed by an outervernier adjustment handwheel. Assembled in this manner, access to thegear trains for servicing, replacement, or the like, can be accomplishedboth simply and rapidly by a sequential removal of the handwheels. Thereis no longer any necessity for completely disassembling the microscope,changing the nosepiece adjustment, or otherwise disrupting a microscopesetup. Ideally, any downtime of the microscope can be substantiallycompletely eliminated by merely having at hand a replacement gear box.

The adjustment system includes a nosepiece support having a horizontalcarriage mounted within the microscope arm assembly for vertical guidedmovement in response to vertical movement of an elongated rigid rodaffixed to the carriage. The rod, in turn, is in operative engagementwith the cam. The nosepiece support provides for a direct verticaladjustment in response to rotation of the cam and without reliance oninterposed pivoting linkages. Additional objects and advantages of theinvention will become apparent from the details of construction andmanner of use of the invention as more fully hereinafter described andclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a microscope incorporating thefeatures of the present invention, portions thereof being broken awayfor purposes of illustration;

FIG. 2 is an enlarged transverse sectional view through the coarse andfine adjustment mechanism with the handwheels and gear box outwardlypositioned;

FIG. 3 is a top plan view of the microscope with a portion of the topwall of the arm assembly removed;

FIG. 4 is a transverse section taken generally in line 4--4 of FIG. 3;

FIG. 5 is an exploded perspective view of the components of the coarseand fine adjustment mechanism.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring now more specifically to the drawings, reference numeral 2designates a microscope incorporating the features of the invention.This microscope includes a base 4 with a support arm 6 extendingupwardly from the base, the base 4 and support arm 6 combining to formthe microscope frame 8. The microscope 2 also will include, mounted tothe frame, one or more eyepieces (not illustrated), a nosepiece 10 and astage 12 therebelow.

The nosepiece 10 is mounted for vertical adjustment through a support orsupport system 14 received within the support arm 6. This support system14 includes a horizontal carriage, within a horizontal extension of thesupport arm, positioned in generally parallel upwardly spaced overlyingrelation to the base 4. The carriage 16 basically comprises a planarpanel member 18 with an upstanding peripheral wall 20 and a reinforcinggrid of integral upstanding ribs 22.

A cylindrical boss 24 depends from the outer end portion of the carriage16 for a telescopic reception of the upper portion of the nosepiece 10therein For retention of the nosepiece, it is proposed that an undercutshoulder or dovetail configuration 26 be defined about the boss-receivedportion of the nosepiece with the boss mounting three selectivelyadjustable retaining screws 28 engageable within the dovetail,preferably in a manner as to allow for a rotational adjustment andcentration of the nosepiece to the optical path.

The second end of the carriage 16, aligned over the vertical portion ofthe arm assembly 6, includes two vertically directed integral splitsleeves 30 and 30A which receive and rigidly clamp to the upper endportion of a vertical rod or shaft 32. The rod 32 depends from thecarriage 16 and is rotatably received within a pair of vertically spacedsleeve bearings 34, each mounted within split sleeves 36 integrallyformed with an adjoining portion of the frame 8. A block 38 is mountedrigid with the lower end of the rod 32 and in turn mounts a laterallyoffset cam follower 40 which rides on the upper edge of cam 42 and isretained in following relation thereto by the weight of the supportsystem 14. Pin 44 projecting laterally from block 38 loosely entersgroove 46 on the lateral face of cam 42 as a safety precaution, allowingand limiting the amount cam roller 40 can lift off of cam 42 when thedownward movement of the carriage 16 is impeded for any reason.

As will be appreciated, the support or support system 14 for thenosepiece 10, responsive to rotation of the cam 42, adjusts or shiftsvertically without pivotal movement and as an integral rigid unit asdetailed in FIGS. 3 and 4. In order to assist this vertical adjustmentand maintain lateral stability for the remote, nosepiece-supporting endof the carriage 16, a pair of opposed guide rollers 48 mount withinvertical channels 50 on the opposed walls 52 of the horizontal portionof the support arm assembly. One of rollers 48, noting FIGS. 3 and 4will normally be spring-loaded, opposing other fixed roller 48, therebyproviding a fixed position for the cylindrical portion 24 of thecarriage 16 with both rollers 48 engaging against flats 54 on thealigned portions of the carriage 16.

Referring now to FIG. 2, a sectional view is shown of the adjustmentmechanism, including cam 42, and its association with the rod 32 of thesupport system. Attention is also directed to FIG. 5 wherein thecomponents of the adjustment mechanism are detailed. The adjustmentsystem mounts transversely through the support arm 6 and, in particular,between and through opposed mounting plates 56 and 58 in opposed armwalls 60 and 62 respectively.

An elongate quill shaft 64 traverses the support arm and projectsoutwardly of the opposed wall mounting plates 56 and 58. A relativelyshorter cam shaft 66 is received over quill shaft 64 and extends throughmounting plate 56. The inner portion of the cam shaft 66 within thesupport arm assembly mounts the cam 42, locked thereto by appropriatemeans such as set screw 68. The outer end of cam shaft 66, outward ofwall 60 and mounting plate 56, has an integrally formed gear 70 thereonTwo flanged bearings 72 are pressed into opposed ends of the cam shaft66 and are free to rotate on quill shaft 64. An elongate central shaft74, defining the gear train system drive shaft, is rotatably receivedthrough the quill shaft 64 and projects beyond the opposed outer endportions thereof. Appropriate bushings, as at 76, may be provided. Theend portion of the drive shaft 74, beyond wall 60, includes an integraldrive pinion 78 immediately outward of the corresponding end of quillshaft 64.

Attention is now directed to the construction illustrated to the left inFIG. 2, at and beyond the wall 60 and mounting plate 56. Thisconstruction, detailed in FIG. 5, includes a gear box assembly 80particularly adapted to mount as a unit on the exposed shaft endportions and in engagement with cam gear 70 and drive gear 78. The gearbox asembly 80 includes inner and outer gear box plates 82 and 84, anintermediate spacer block 86 and spacer posts 88 between the block 86and inner plate 82.

The gear train system comprises dual generally duplicate gear trainsincluding a first pair of compound gears 90, each having a reductiongear 92 adjacent outer gear box plate 84 and an inwardly extendingelongate pinion gear 94 which is freely rotatably received throughspacer block 86 and extends inwardly thereof The compound gears 90 mounton elongate shafts, the ends of which are received in the opposed boxplates 82 and 84, and are so oriented as to drivingly engage thereduction gears 92 with the drive gear 78 of shaft 74.

Inward of the spacer block 86 is a second pair of compound gears 96,each including a reduction gear 98 meshed with a pinion 94 of acorresponding compound gear 90. The compound gears 96 in turn includeintegral pinions 100 inwardly directed. Noting the detail of FIG. 5, theouter face of the reduction gear 98 of one of the compound gears 96 isprovided with an outwardly directed pin 102 which rotatably aligns withan abutment or abutment pin 104 on and inwardly directed from the innerface of spacer block 86, providing for a rotational limit to theassociated compound gear 96, and hence the gears drivingly associatedtherewith.

The pinion 100, associated with the compound gear 96 incorporating thelimit pin 102, meshes with reduction gear 106 of a compound gear 108which includes an integral pinion gear 110.

A compound gear 112 is provided as a companion to the compound gear 108and includes reduction and pinion gears 114 and 116 of equal size asgears 106 and 110 respectively and joined by an internal coiled torsionspring 115 therebetween. The two pinion gears 110 and 116 mesh indriving engagement with the cam gear 70 whereby a rotation of the gearbox assembly 80 in its entirety will effect a direct or coarseadjustment of the cam shaft 66. On the other hand, operation of the geartrains, through a rotational driving of driveshaft 74, will effect afine or vernier rotation of the cam pinion 70 and cam shaft 66.

The use of dual gear trains is significant in stabilizing and enhancingthe precision of the vernier adjustment. A significant furthercontribution is derived from the spring loaded compound gear 112 in thatthe coiled torsion spring 115, acting to resiliently bias the associatedgears 114 and 116 in opposite directions, maintains both these twogears, and through them all of the gears of the assembled system, inintimate seated or meshed engagement. This in turn removes any tendencyfor backlash or lost motion within the gear train system, while at thesame time allowing for manufacturing tolerances and avoiding thenecessity of the use of high precision formed gears. It will also berecognized that the construction, as proposed, will provide for anautomatic accommodation of some degree of system wear.

An inner handwheel 118, for coarse adjustment, is telescopicallyreceived over the gear box assembly 80, defining in effect a housingtherefor. The gear box assembly 80 is secured to and within the innerhandwheel 118 by appropriate threaded fasteners 120 engaged through theinner gear box plate 82 and a plate supporting shoulder or pair ofopposed shoulders 122 interiorly of the handwheel 118. The handwheel 118can include an inwardly directed alignment pin 124 receivable through aguide aperture 126 in the inner mounting plate 82 to provide rotationallimits when engaged with two pins 160 mounted outwardly in plate 56. Thegear box assembly 80 with the handwheel 118 attached is then secured tothe quill shaft 64 with set screws 161. An outer handwheel 128, for fineor vernier adjustment, is secured to the outer end portion of thecentral driveshaft 74 outward of drive pinion 78. The handwheel 128 ismounted between an outer retaining clip 130 and multiple annular or discsprings 132 engaged between the pinion 78 and the inner face of thevernier handwheel 128. Mounted in this manner, the outer handwheel 128,upon the introduction of a rotational overload, will tend to slip ratherthan overextend the capability of the gear train.

It will also be noted that the outer handwheel 128 includes an inwardlydirected annular flange or skirt 134 which is received within anoutwardly directed annular groove 136 about the inner handwheel 118,thus providing for a rotatable mating therebetween in a manner whichallows for a rotation of the handwheels independently with each other inconjunction with a retention of the inner handwheel 118 by the outerhandwheel 128.

Turning now to the right hand portion of FIG. 2, inner and outerhandwheels, 138 and 140 respectively, are provided to duplicate theadjustment capability of the handwheels 118 and 128. The auxiliary innerhandwheel 138, for coarse adjustment, is locked to the quill shaft 64for a direct rotation thereof and the cam shaft 66 therewith. The outerauxiliary handwheel 140, for fine or vernier adjustment, mounts to theinner driveshaft 74 for direct rotation thereof and the gear trainsystem therethrough The auxiliary outer handwheel 140 is clip and springmounted in the manner of the handwheel 128. Appropriate annular or discspring assemblies 142, engaged with the opposed faces of the innerhandwheel 138 and incorporating one or more shaft-mounted clips 144, arealso present and provide a braking action holding the adjusted positionof the inner handwheels 118 and 138 during rotation of the outerhandwheels 128 and 140.

In operation, rotation of either or both inner handwheels 118 and 138effect a direct rotation of the cam shaft 66 and cam 42 for a coarseadjustment of the vertically movable support assembly. It should beappreciated that the cam 42, acting on the follower 40, operates toelevate the nosepiece. Lowering of the nosepiece will normally beeffected by the weight of the support assembly itself, as the cam 42 isrotated in the opposite direction.

When fine adjustment of the vertical position of the nosepiece isdesired, the inner handwheels 118 and 138 are released and the outerhandwheels 128 and 140, individually or together, rotated. Rotation ofthese handwheels effects a direct rotation of the driveshaft 74 anddrive pinion 78. This in turn drives the gear trains within the gear boxassembly and, in turn, the cam pinion 70. Rotation of the gear trainswill be limited by limit pin 102 engaging abutment 104 to ten turns ofthe outer handwheels 128 and 140.

As previously indicated, a particularly significant feature of theinvention is the ready accessibility of the gear box assembly and geartrain system itself for servicing or replacement without necessitating adisassembling of the microscope frame and with little or nointerruption. From the above detailed description of the constructioninvolved, it will be appreciated that, basically, upon a removal of theouter retaining clips which retain the outer handwheels 128 and 140, andloosening the set screw 161 in gear box 80, the remaining operatingcomponents, including the inner handwheels and gear box assembly, can beeasily slipped from the mounting shafts. Similarly, the centraldriveshaft 74 itself can be easily withdrawn. Should the gear boxassembly or gear trains require servicing, a substitute assembly can bequickly slid into position, the handwheels remounted and the entireapparatus put back into service with only a few moments delay and noappreciable downtime. The gear box assembly is self-contained and,through the torsion loaded nature of one of the compound gears, readilyengaged in operative relationship with the cam gear 70.

The foregoing description of an embodiment of this invention is given byway of illustration and not of limitation. The concept and scope of theinvention are limited only by the following claims and equivalentsthereof which may occur to others skilled in the art.

I claim:
 1. A microscope having a frame comprising a base and an armassembly extending upwardly therefrom, a nosepiece, and an adjustmentsystem for moving said nosepiece relative to said arm assembly, saidadjustment system including:a nosepiece support mounted on said armassembly for movement relative thereto, said arm assembly includingopposed walls, a quill shaft traversing said arm assembly between saidopposed walls and including a first end portion extending beyond a firstof said walls, a cam shaft rotatably mounted on said frame, a cam fixedto said cam shaft for rotation therewith, said cam being operativelyengaged with said nosepiece support for movement thereof to effectadjustment of said nosepiece, said cam shaft having a free drive endremote from said cam and including a cam shaft pinion, said cam shaftextending transversely within said arm assembly with the free drive endand cam shaft pinion positioned outwardly of the arm assembly and saidcam shaft encircling a portion of the length of said quill shaft at saidfirst end portion, and permitted to rotate relative to the quill shaft,said quill shaft including a second end portion extending beyond thesecond of said walls, a reduction gear train system releasably engagedwith the free drive end of said cam shaft for rotation thereof andselective direct removal therefrom, said gear train system comprisingmultiple drivingly engaged gears, a gear box mounting said reductiontrain system, a coarse adjustment handwheel mounted to said gear boxwhereby rotation of said gear box, gear train system, cam shaft and camas a unit, said coarse adjustment handwheel, gear box and gear trainsystem being removable as a unit from the drive end of said cam shaft,an auxiliary coarse adjustment handwheel fixed to the second end or saidquill shaft for rotation thereof and the cam shaft therewith, a geartrain drive shaft operatively engaged with the gears of said gear trainsystem and slidably engaging said cam shaft pinion, and a vernierhandwheel mounted to said gear train drive shaft whereby rotation ofsaid vernier handwheel is effective to rotate the gears of said geartrain system with a resultant rotation of the cam shaft and cam, saiddrive shaft being removably received through said quill shaft, saiddrive shaft having a first end portion projecting beyond the first endportion of said quill shaft and including a drive pinion thereon, saiddrive pinion engaging said gear train system, said vernier handwheelremovably mounted on said drive shaft first end portion outward of thedrive pinion, said nosepiece support comprising a carriage overlyingsaid base in spaced relation thereabove, a vertical rod rigid with anddepending from said carriage, bearing means mounting said rod to saidarm assembly for vertical reciprocation relative thereto to effect acorresponding vertical adjustment of said carriage relative to saidbase, means on said carriage remote from said rod for mounting saidnosepiece, and follower means engaged between said rod and said cam forvertical adjustment of said rod and said carriage in response torotation of said cam.
 2. The apparatus of claim claim 1 wherein saidcarriage is mounted for vertical adjustment within said arm assembly,and guide means engaged between said arm assembly and said carriage forfacilitating and guiding said carriage during vertical adjustmentthereof.
 3. The apparatus of claim 2 wherein said carriage comprises apanel member, said means for mounting said nosepiece comprising adepending boss on said panel member and means within said boss receivingand retaining said nosepiece.
 4. The apparatus of claim 13 wherein saidgear train system includes first and second compound gears positionablein direct driven engagement with said drive pinion, third and fourthcompound gears in driven engagement respectively with the first andsecond compound gears, each of said third and fourth compounds gearscomprising a reduction gear and a reduced diameter pinion integraltherewith, and fifth and sixth compound gears, said fifth compound gearincluding a reduction gear in driven engagement with the pinion of saidthird compound gear, and an integral pinion positionable in drivingengagement with said cam gear, said sixth compound gear comprising areduction gear in driven engagement with the pinion of the fourthcompound gear, a drive pinion positionable in driving engagement withthe cam gear, and a limited movement coupling between the reduction gearand the pinion gear of the sixth compound gear.
 5. The apparatus ofclaim 4 including a limit means on said gear train limiting rotationaldriving of the gears thereof to ten turns of the vernier handwheel. 6.The apparatus of claim 5 wherein said limit means comprises a limit pinon one of said gears and a selectively engageable abutment rigid withsaid gear box.
 7. A microscope having a frame comprising a base and anarm assembly extendng upwardly therefrom, a nosepice, and an adjustmentsystem for moving said nosepiece relative to said arm assembly, saidadjustment system including:a nosepiece support mounted on said armassembly for movement relative thereto, a cam shaft rotatably mounted onsaid frame, a cam fixed to said cam shaft for rotation therewith, saidcam being operatively engaged with said nosepiece suport for movementthereof to effect adjustment of said nosepiece, said cam shaft having afree drive end remote from said cam, a reduction gear train systemreleasably engaged with the free drive end of said cam shaft forrotation thereof and selective direct removal therefrom, said gear trainsystem comprising multiple drivingly engaged gears, a gear box mountingsaid reduction gear train system, a coarse adjustment handwheel mountedto said gear box whereby rotation of said coarse adjustment handwheel iseffective to rotate said gear box, gear train system, cam shaft and camas a unit, said coarse adjustment handwheel, gear box and gear trainsystem being removable as a unit from the drive end of said cam shaft, agear train drive shaft operatively engaged with the gears of said geartrain system, and a vernier handwheel mounted to said gear train driveshaft whereby rotation of said vernier handwheel is effective to rotatethe gears of said gear train system with a resultant rotation of the camshaft and cam, said nosepiece support comprising a carriage overlyingsaid base in spaced relation thereabove, a vertical rod rigid with anddepending from said carriage, bearing means mounting said rod to saidarm assembly for vertical reciprocation relative thereto to effect acorresponding vertical adjustment of said carriage relative to saidbase, means on said carriage remote from said rod for mounting saidnosepiece, and follower means engaged between said rod and said cam forvertical adjustment of said rod and said carriage in response torotation of said cam.
 8. The apparatus of claim 7 wherein said carriageis mounted for vertical adjustment within said arm assembly, and guidemeans engaged between said arm assembly and said carriage forfacilitating and guiding said carriage during vertical adjustmentthereof.
 9. The apparatus of claim 8 wherein said carriage comprises apanel member, said means for mounting said nosepiece comprising adepending boss on said panel member and means within said bossreceiving, adjusting and retaining said nosepiece.
 10. A microscopehaving a frame comprising a base and an arm assembly extending upwardtherefrom, a nosepiece, and an adjustment system for moving saidnosepiece relative to said arm assembly, said adjustment systemincluding a nosepiece support mounted on said arm assembly for movementrelative thereto, a cam shaft rotatably mounted on said frame, means formanually rotating said shaft relative to said frame, a cam fixed to saidcam shaft for rotation therewith, said nosepiece support comprising acarriage overlying said base in spaced relation thereabove, a verticalrod rigid with and depending from said carriage, sleeve bearing meansattached to said base and slidably receiving said rod at two locationsalong the length thereof for guiding said rod in a vertical direction assaid rod is moved relative to said base so that said carriage isadjusted vertically relative to said base as said rod is movedvertically, means on said carriage remote from said rod for mountingsaid nosepiece, and follower means connected to said rod and inoperative engagement with said cam for vertical adjustment of said rodand said carriage in response to rotation of said cam so that rotationof said cam during a carriage-adjustment operation moves the area ofengagement between said follower and said cam along a substantiallyvertical path of movement to vertically move said rod relative to saidbase and thereby vertically adjust said carriage as aforesaid.
 11. Theapparatus of claim 10 wherein said carriage is mounted for verticaladjustment within said arm assembly, and guide means engaged betweensaid arm assembly and said carriage for facilitating and guiding saidcarriage during vertical adjustment thereof.
 12. The apparatus of claim11 wherein said carriage comprises a panel member, said means formounting said nosepiece comprising a depending boss on said panel memberand means within said boss receiving and retaining said nosepiece.
 13. Amicroscope having a frame comprising a base and an arm extendingupwardly therefrom, a nosepiece, and an adjustment system for movingsaid nosepiece relative to said arm assembly, said adjustment systemincluding a nosepiece support mounted on said arm assembly for movementrelative thereto, a cam shaft rotatably mounted on said frame, a camfixed to said cam shaft for rotation therewith, said nosepiece supportcomprising a carriage overlying said base in spaced relation thereabove,a vertical rod rigid with and depending from said carriage, bearingmeans mounting said rod to said arm assembly and permitting a verticaladjustment of said carriage relative to said base as said rod is guidedvertically along and relative to said bearing means, and follower meansconnected to said rod and in operative engagement with said cam forvertical adjustment of said and carriage in response to rotation of saidcam, said carriage including mounting means remote from said rod formounting said nosepiece to said carriage, said mounting means includingmeans defining a generally circular and horizontally-oriented openingand said nosepiece including a frustoconical-shaped member rotatablyreceived by said circular opening in a dovetail fashion with the smallend of said frustoconical-shaped member directed downwardly to permitrotational adjustment of said nosepiece relative to said carriage assaid frustoconical-shaped member is rotated within said circular openingand relative to said mounting means.